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<h4>Synopsis</h4>
Address: 127.127.34.<i>u</i><br>
Reference ID: <tt>WWVB</tt><br>
Driver ID: <tt>ULINK</tt><br>
Serial Port: <tt>/dev/wwvb<i>u</i></tt>; 9600 bps, 8-bits, no parity<br>
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Features: <tt>(none)</tt>
<h4>Description</h4>
<p>This driver supports the Ultralink Model 325 (replacement for Model 320) RS-232 powered WWVB receiver. PDF specs available on <a href="http://www.ulio.com/">http://www.ulio.com/</a>. This driver also supports the Model 320, 330,331,332 decoders in both polled or continous time code mode.<br>
Leap second and quality are supported.</p>
<p>Most of this code is originally from refclock_wwvb.c with thanks. Any mistakes are mine. Any improvements are welcome.</p>
<hr>
<pre> The Model 325 timecode format is:
<cr><lf>RQ_1C00LYYYY+DDDUTCS_HH:MM:SSL+5
where:
R = Signal readability indicator, ranging from R1 to R5
Q R1 is unreadable, R5 is best reception
_ = Space
1 = prev. received data bit, values: 0, 1 ,M or ? unknown
C = Signal reception from (C)olorado or (H)awaii
0 = Hours since last WWVB time and flag code update, values
0 00 to 99 (hopefully always 00)
L = HEX A5 if receiver is locked to WWVB, Space if not
YYYY = Year from 2000 to 2099
+ = '+' if current year is a leap year, else ' '
DDD = current day in the year from 1 to 365/366
UTC = timezone (always UTC)
S = Daylight savings indicator, (S)TD, (D)ST, (O) transition
into DST, (I) transition out of DST
_ = Space
HH = UTC hour 0 to 23
: = Time delimiter, ':' if synced, Space if not
MM = Minutes of current hour from 0 to 59
: = Time delimiter, ':' if synced, Space if not
SS = Seconds of current minute from 0 to 59
mm = 10's milliseconds of the current second from 00 to 99
L = Leap second pending at end of month, (I)nsert, (D)elete
or Space
+5 = UT1 correction, +/- .1 sec increments
</pre>
<p>Note that Model 325 reports a very similar output like Model 33X series. The driver for this clock is similar to Model 33X behavior. On a unmodified new ULM325 clock, the polling flag (flag1 =1) needs to be set.</p>
<hr>
<pre> The Model 320 timecode format is:
<cr><lf>SQRYYYYDDD+HH:MM:SS.mmLT<cr>
where:
S = 'S' -- sync'd in last hour, '0'-'9' - hours x 10 since last update, else '?'
Q = Number of correlating time-frames, from 0 to 5
R = 'R' -- reception in progress, 'N' -- Noisy reception, ' ' -- standby mode
YYYY = year from 1990 to 2089
DDD = current day from 1 to 366
+ = '+' if current year is a leap year, else ' '
HH = UTC hour 0 to 23
MM = Minutes of current hour from 0 to 59
SS = Seconds of current minute from 0 to 59
mm = 10's milliseconds of the current second from 00 to 99
L = Leap second pending at end of month -- 'I' = inset, 'D'=delete
T = DST <-> STD transition indicators
</pre>
<p>Note that this driver does not do anything with the T flag.</p>
<p>The M320 also has a 'U' command which returns UT1 correction information. It is not used in this driver.</p>
<hr>
<pre> The Model 33x timecode format is:
S9+D 00 YYYY+DDDUTCS HH:MM:SSl+5
Where:
S = sync indicator S insync N not in sync
the sync flag is WWVB decoder sync
nothing to do with time being correct
9+ = signal level 0 thru 9+ If over 9 indicated as 9+
D = data bit ( fun to watch but useless ;-)
space
00 = hours since last GOOD WWVB frame sync
space
YYYY = current year
+ = leap year indicator
DDD = day of year
UTC = timezone (always UTC)
S = daylight savings indicator
space
HH = hours
: = This is the REAL in sync indicator (: = insync)
MM = minutes
: = : = in sync ? = NOT in sync
SS = seconds
L = leap second flag
+5 = UT1 correction (sign + digit ))
</pre>
<p>This driver ignores UT1 correction,DST indicator,Leap year and signal level.</p>
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<h4>Fudge factors</h4>
<p>flag1 polling enable (1=poll 0=no poll)</p>
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<address><a href="mailto:frank.migge@oracle.com">mail</a></address>
<!-- hhmts start -->Last modified: Mon Mar 8 10:12:08 PST 2004<!-- hhmts end -->
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